How do I apply a condition only if the total amount is less than a specific amount?

[on3ss]

I'm building an ecommerce where my client have a policy of free shipping after the total order crosses a certain price, how do I achieve this?

[frezno]

you can define the order value(s) which apply for free shipping in a config file (or in the DB) and check with the subTotal whether this value is reached or not. Best owuld be to write an own method for calculating the shipping costs.